1. Field of The Invention
The invention relates to an electrical connector, particularly to a Universal Serial Bus (USB) connector having shielding device thereon for latchably coupling to a complementary cable connector.
2. The Prior Art
There is a trend in the computer field to use USB connectors in place of most of the I/O connectors, such as D-Sub connectors and Mini-Dins. As can be seen in FIG. 1, a USB connector disclosed in Taiwan Patent Applications Nos. 84213585 and 84213586 assigned to the same applicant, generally designated at 1, mainly comprises an insulating housing 2, a front shell 3 and a rear shell 4. In assembling, a number of contacts (not shown) will be disposed in the housing and these contacts extend downward out of the housing 2 for wave soldering to an exterior circuit board. Thus, the transmission of electrical signals may be prevented from external electromagnetic interference owing to the shielding device. Other similar connectors of this type and their related parts can be found in Taiwan Patent Applications Nos. 85301901, 85301709, 79203382, 79204719, 79203005, 79211295, 81200270, 81204407, 82217806, 83101476 and 85202863. These connectors, however, encounter some problems.
In wave soldering, molten solders and flux may be sucked into the connectors owing to capillary effect because the bottoms of the connectors get too close to the surface of the circuit board they resting on. The molten solders and flux penetrated into the interior of the connectors may do harm to the transmission of electrical signals.
In addition, the housings of traditional connectors fall into the vertical type connectors and the horizontal type connectors to meet the requirements of different insertion directions of a mating connector. This increases both the manufacturing cost of the manufacturer and the inventory cost of the vendor.
Moreover, in some of the conventional connectors which grounding tabs are attached to the shielding device, different grounding tabs are attached to the shielding devices by means of various different securing means, such as bolt and nuts, fasteners, etc.; this also increases the inventory cost. While in the other conventional connectors which grounding tabs are integrally formed on the shielding device, such as the one disclosed in FIG. 1, a number of inward deflected grounding tabs 7 are integrally formed on the peripheries of a pair of symmetric openings 6 defined in the front surface of the shell 3 for engagement with the metal casing of a mating connector (not shown) to constitute grounding paths for the connector 1. This shielding device, however, has the shortcoming that it is difficult for a mating connector to be withdrawn from the connector 1 owing to the inward deflected grounding tabs 7.
Besides, some conventional connectors do not include grounding means possessing clipping function on their shielding devices, and thus may not provide an excellent engagement effect to a mating connector. Other connectors, though include grounding means possessing clipping function on their shielding devices, still provide poor engagement effect to a mating connector.
Furthermore, traditional connectors have a lower strength due to their structures, which encounter a deformation problem of the shielding device while a mating connector is inserted or withdrawn therefrom.
Hence, there is a need for a shielded electrical connector at can overcome the above-mentioned problems and shortcomings.